Converter arrangement having a control die with control logic for generating a control signal and a control output for controlling a converter die

ABSTRACT

A converter arrangement, in particular a switched DC/DC converter arrangement, comprises a control die and a converter die. The control die comprises a control logic for generating a control signal and a control output for controlling the converter die by means of the control signal. The converter die comprises at least one converter that is designed for converting an input signal into an output signal in dependence on the control signal, wherein the control signal can be received at a control input. A single-line interface connects the control output to the control input.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 14/409,746, filed Dec. 19, 2014, which is the national stage ofInternational Patent Application No. PCT/EP2013/062799, filed Jun. 19,2013, which claims the benefit of German Patent Application No.102012105694.3 filed on Jun. 28, 2012, all of which are herebyincorporated by reference in their entirety for all purposes.

The present invention pertains to a converter arrangement, in particulara switched DC/DC converter arrangement. The invention furthermorepertains to a method for operating a converter arrangement, particularlyfor operating a switched DC/DC converter arrangement.

BACKGROUND OF THE INVENTION

The energy management for integrated circuits in customer-specificapplications is increasingly faced with the task of being able tosatisfy a continuously rising power demand. In particular, modernprocessors require high currents that must be made available via powersupply rails or several DC/DC down converters. Accordingly, the controlcircuits (power management units) required for this purpose are becomingmore and more complex, such that the expenditures for making availablehigh currents increase accordingly. Limiting factors in this respectare, for example, the size of the semiconductor substrate used, thenumber of pins and terminals, thermal restrictions due to power losses,as well as restrictions due to the current conducting and the limitedsoldering space.

In the prior art, it is known to utilize external transistors in orderto reduce the complexity of integrated circuits for energy managementand to simultaneously make available high currents. In this way, thesupply path (power path) can be separated from the central control unit(power management integrated circuit or PMIC). Although the utilizationof external transistors allows a simpler design of the PMICs, thisarrangement has a number of disadvantages. For example, multipleterminals (pins) are required for implementing a conventional currentmode DC/DC converter (current mode). Furthermore, currently availableexternal transistors only have a low switching frequency and thereforeslow rise and fall times. This makes it necessary to utilize coils withhigher impedance that further reduce the efficiency of the DC/DCconverter. This may be particularly critical in applications withprocessors that require a plurality of power supplies. There is a needin the art for a converter arrangement with reduced complexity, as wellas the capability of making available high currents.

SUMMARY OF THE INVENTION

According to an embodiment of the invention, a converter arrangementcomprises a control die and a converter die. The converter arrangementmay be realized, in particular, in the form of a switched DC/DCconverter arrangement.

The control die furthermore comprises a control logic in order togenerate a control signal. The converter die comprises at least oneDC/DC converter that is designed for converting an input signal into anoutput signal in dependence on the control signal. The control die andthe converter die are connected by means of a single-line interface.This single-line interface connects the control output of the controldie to the control input of the converter die.

The control die or the control logic of the control die respectivelygenerates the control signal in order to control the converter die withthis control sign al via the control output. For example, the controlsignal is used for adjusting a duty factor (duty cycle) of the converterdie. The at least one DC/DC converter transforms the input signal intothe output signal in dependence on the control signal.

In this case, the term “single-line interface” refers to an interfacethat is designed for transmitting a signal in two different directions.In the present instance, the control signal generated by the control dieis transmitted in a first transmitting direction from the control outputof the control die to the control input of the converter die by means ofthe single-line interface. Information or generally signals can likewisebe transmitted in a second transmitting direction from the control inputof the converter die to the control output of the control die. Thetransmission in both directions takes place via one individual line.

Furthermore, the term module or die refers to a semiconductor chip or“die,” wherein the latter refers in the field of integrated circuits toa semiconductor material that comprises a functional integrated circuit.

The proposed implementation of separate control and converter diesallows a less complex design of the entire converter arrangement and issimultaneously capable of making high electric currents available. Forexample, the converter die may comprise one or more DC/DC converters,for example, with corresponding DC/DC transistors, as well ascorresponding drivers for these transistors, current measuring devicesand zero comparators, in a single structure that is realized, separatelyfrom the control die. Other components that are typically used in aconverter arrangement are included in the control logic. For example,the control logic comprises a feedback path, a control path, apulse-width modulator and a voltage selector. These components arelikewise integrated into a separate module.

In comparison with solutions known from the prior art that utilizeexternal transistors, the proposed solution has a reduced number ofterminals (pins). External terminals for such transistors are notrequired. Since it is possible to forego external transistors, theswitching frequency of the present arrangement is improved in comparisonwith these solutions. The switching frequency can be increased, inparticular, for switched DC/DC converters such that lower inductancescan be used with the converter arrangement. This also has the advantagethat smaller module sizes and consequently lower production costs can berealized. The efficiency of the converter arrangement can ultimatelyalso be increased due to the higher switching frequencies and the optionof using lower inductances.

According to another embodiment of the invention, the single-lineinterface is designed for bidirectional communication between thecontrol out and the control input. This bidirectional communicationallows the transmission of signals in the above-defined first and secondtransmitting directions. The control signal may be transmitted from thecontrol die to the converter die in order to respectively adjust a dutyfactor or duty cycle of the converter die. Information on a coil currentand/or a temperature of the module or the coil can be transmitted in thesecond transmitting, direction. This makes it possible, for example, todetect excessively high temperatures. It is generally possible tosimultaneously transmit signals in both transmitting directions.However, typically the transmission initially takes place in onedirection and is followed by a transmission in the other direction.

According to another embodiment of the invention, the bidirectionalcommunication is designed for the transmission of the control signalfrom the control output to the control input, as well as for thereception of a current signal that is transmitted from the control inputto the control output. In this case, the current signal depends on thecurrent flowing through a coil that can be connected to the at least oneDC/DC converter.

In conventional converter arrangements, at least one coil is externallyconnected to the integrated circuit. However, it is also possible tointegrate the coil into the module structure.

The current flowing through the inductance or coil represents apotential control parameter that is dependent on the operating state ofthe converter itself. The transmission of the corresponding currentsignal with the aid of the bidirectional single-line interface can beused for controlling the converter arrangement. In this way, thesingle-line interface is used for controlling the converter die in onetransmitting direction and for receiving feedback for control purposesin the other transmitting direction.

According to another embodiment of the invention, the control logic ofthe control die generates the control signal in dependence on thecurrent signal.

The current signal is a measure for the current flowing through theconnected inductance or coil and can be used as control parameter. Forexample, the current signal indicates the electric current that flowsthrough the coil and, for example, should remain within certain limits.The control makes it possible for the current signal to remain withinpredefined threshold values. As soon as the current deviates from theseranges, the control can intervene by correspondingly adapting thecontrol signal with the aid of the control logic.

According to another embodiment of the invention, the control logiccomprises a feedback or return input that is connected to a feedbackoutput (or return output) of the converter die.

The converter die generates a feedback or return signal in dependence onthe output signal of the (voltage) conversion of the converter die. Thecontrol signal generated by the control logic also depends on thefeedback signal. The feedback signal may indicate the level of theoutput signal. For example, the output signal corresponds to the outputvoltage generated by the at least one DC/DC converter. The feedback ofthis output signal makes it possible to adjust the control signalaccordingly, wherein this may be realized, for example, by adapting theduty factor or the “duty cycle” of the at least one DC/DC converter.

According to another embodiment of the invention, the control logiccomprises a comparator that is coupled to the feedback input.

The comparator is designed for generating a comparison signal bycomparing the current signal and the feedback signal. In this way, twocontrol variables are used for generating the control signal. On the onehand, the control is respectively realized by means of the single-lineinterface or the transmission of the current signal that indicates thecurrent flowing through the connected inductance or coil. On the otherhand, the control is realized by means of the feedback or return signalthat is dependent on the output signal. For example, the feedback signalindicates the output voltage of the at least one DC/DC converter and isaccordingly used for adjusting the control signal.

According to another embodiment of the invention, the control logiccomprises a modulator for modulating the control signal based on apulse-width modulation. In this case, the modulation depends on thecomparison signal of the comparator. Furthermore, the thusly pulse-widthmodulated control signal defines the duty factor or “duty cycle” of theat least one DC/DC converter. This embodiment with an auxiliarymodulation is particularly advantageous when a switched “current mode”converter arrangement is used.

According to another embodiment of the invention, the converter diecomprises the at least one DC/DC converter that also features switches.Potential switches include, for example, “power switches.” Anadditionally provided converter control logic is connected to thecontrol input, as well as connected to the switches via driver stages.Furthermore, a provided power source is connected to the control inputand coupled to a current meter.

The switches are likewise integrated into the same semiconductor chiptogether with the converter control logic, i.e. the driver stages areconnected to the switches. The current source and the current meter arelikewise integrated into the same semiconductor structure.

At the control input, the converter die receives the control signal thatconsequently is applied to the driver stages. The driver stages aredesigned for driving the switches in accordance with the control signal.The current meter is used for measuring the current signal thatindicates the current flowing through the connected coil. The currentsignal is tapped b this current meter and made available at the controlinput by means of the current source. In this way, the current signalcan be transmitted to the control output of the control die by means ofthe single-line interface.

According to another embodiment of the invention, the control diecomprises a temperature input. In addition, the converter die comprisesa temperature output. A second single-line interface is provided andconnects the temperature input to the temperature output.

According to another embodiment of the invention, the second single-lineinterface is designed for bidirectional communication between thetemperature input and the temperature output.

Similar to the above-discussed first single-line interface, the secondsingle-line interface is also designed for transmitting signals in twodifferent transmitting directions—in this case from the temperatureinput to the temperature output and vice versa.

According to another embodiment of the invention, the converter diefeatures means for generating a temperature signal in dependence on thetemperature of the converter die. This temperature signal is madeavailable at the temperature output and transmitted to the temperatureinput of the control die by means of the second single-line interface.In this way, temperature information that indicates, for example, thetemperature of the semiconductor chip or the coil can be made availableto the control die such that this temperature information can be takeninto consideration in making available the control signal.

According to another embodiment of the invention, the bidirectionalcommunication is designed for transmitting the temperature signal fromthe temperature output to the temperature input, as well as forreceiving a configuration signal from the temperature input at thetemperature output.

According to another embodiment of the invention, the control logicswitches the converter die on or off and/or adjusts a BIAS current atthe converter die in dependence on the configuration signal. In otherwords, the second single-line interface can be utilized similarly to thefirst single-line interface. This means that it is possible to transmitand receive signals, in this case for example the temperature signal andthe configuration signal, in two transmitting directions by means of thesecond single-line interface.

According to another embodiment of the invention, the converter diecomprises a plurality of control logics that respectively featurecorresponding control outputs. In addition, the converter die comprisesa plurality of converters and corresponding control inputs.

Each control logic can control a corresponding converter by means ofrespective control signals. For this purpose, the converter diecomprises one or more DC/DC converters that are referred to as phases.For example, the converters are integrated into one common semiconductorbody or distributed over different separate components.

The proposed design allows a flexible implementation of the converterarrangement for an effective power management. The number of individualphases can largely be chosen arbitrarily and adapted to thecorresponding task. High electric currents for several voltage suppliescan be realized.

According to another embodiment of the invention, the plurality ofcontrol logics is integrated into a common semiconductor body. Theplurality of converters is integrated into another common semiconductorbody.

According to another embodiment of the invention, the plurality ofcontrol logics respectively use or share a common return or feedbackinput. This is connected to a feedback output of the plurality ofconverters. The feedback or return path that connects the feedback inputto the comparator can be identical for all or at least some of thecontrol logics.

According to an embodiment of the invention, a method for operating, aconverter arrangement, particularly for operating a switched voltageconverter, initially comprises the generation of a control signal bymeans of a control logic in a control die in order to control aconverter die by means of the control signal. In addition, the controlsignal is transmitted by means of a first single-line interface thatconnects the control output of the control die to a control input of theconverter die. The control signal is received at the control input ofthe converter die, and at least one DC/DC converter of the converter dieconverts an input signal into an output signal in dependence on thecontrol signal.

The proposed method respectively utilizes separate or separated controland converter dies and in this way allows a simpler design and thereforea simpler operation of the entire converter arrangement. This makes itpossible to make available high electric currents. In comparison withsolutions known from the prior art, it is possible to forego theutilization of external transistors and therefore to reduce the numberof eternal terminals (pins), because no external transistors have to beconnected. The switching frequency of the converter arrangement isthereby increased and makes it possible to utilize lower inductancesthat are typically used with the arrangement. This also provides theadvantage of reduced module sizes and consequently lower productioncosts. The faster switching frequency and the utilization of lowerinductances ultimately make it possible to improve the efficiency of theentire converter arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

Several embodiment examples of the invention are described in greaterdetail below with reference to the figures. The description of circuitcomponents or modules that correspond with respect to their function isnot repeated in each of the following figures.

In these figures:

FIG. 1 shows an embodiment example of a converter arrangement accordingto the proposed principle,

FIG. 2 shows another embodiment example of a converter arrangementaccording to the proposed principle,

FIG. 3 shows an example flowchart of a converter arrangement accordingto the proposed principle,

FIG. 4 shows another embodiment example of a converter arrangementaccording to the proposed principle,

FIG. 5 shows an embodiment example of a multi-phase converterarrangement according to the proposed principle,

FIG. 6 shows an embodiment example of an inverting converter arrangementaccording to the proposed principle,

FIG. 7 shows an embodiment example of a converter arrangement accordingto FIG. 6, and

FIG. 8 shows an embodiment example of another multi-phase converterarrangement according to the proposed principle.

DETAILED DESCRIPTION

FIG. 1 shows an embodiment example of a converter arrangement accordingto the proposed principle. The converter arrangement comprises twoseparate components, namely a control die D1 and a converter die D2.Both modules are respectively integrated into different semiconductorblocks. The illustration merely shows function blocks that are discussedin greater detail below with reference to the other figures. In theproposed arrangement, the converter die comprises at least one DC/DCconverter, wherein a first and a second DC/DC converter DCDC1, DCDC2 areillustrated. FIG. 1. These voltage converters respectively comprisetransistors SW1, SW2, means for driving these transistors, currentmeasuring means and (optionally) a zero comparator. The control die ormain module comprises a control logic for controlling the DC/DCconverters of the converter die D2. Other components include a return orfeedback path, a control path, a pulse-width modulator and voltageselection options or other components.

The control die D1 and the converter die D2 are connected to one anothervia different control lines. In this example, the control die D1comprises two control outputs D1_T1, D1_T2 that are respectivelyconnected to corresponding control inputs D2_T1, D2_T2 of the converterdie D2 by means of a single-line interface INT1, INT2. In addition, thecontrol die D1 comprises a feedback input D1_FB that is connected to afeedback output D2_FB of the converter die D2. The control dieultimately also comprises a temperature input D1_TMP that is connectedto a corresponding temperature output D2_TMP of the converter die D2.

The converter die D2 features a supply input, at which a supply voltageVsup can be supplied, as well as an additional input PUSS for supplyinga reference voltage. The control inputs D2_T1, D2_T2 are connected to afirst and a second DC/DC converter. The first and the second DC/DCconverters are connected to corresponding inductance terminals LX1, LX2.These inductance terminals are connected to a first and a second coilL1, L2. The first coil and the second coil L1, L2 are connected to oneanother and also connected to an output Vout of the converter de D2 anda capacitor C. At the connection node between the first and the secondcoil L1, L2, a feedback output D2_FB is connected to the feedback inputD1_FB of the control die D1.

The converter arrangement illustrated in this figure features a voltagefeedback for determining the feedback signal FB of the converter die D2(in this case in dependence on an output voltage Vout). The converterarrangement additionally features a control path for determining acurrent signal sense that represents a measure for the current flowingin the first and the second coil L1, L2. In order to implement thesefeedbacks, the control input and the control output are connected bymeans of the single-line interfaces INT1, INT2. These interfaces aredesigned for bidirectional communication and can transmit the controlsignal PWM from the control die D1 to the converter die D2, as well astransmit the measured current signal I_sense, which indicates theinductance current (common sense) received at the control die D1 due tothe transmission from the converter die D2, in the opposite transmittingdirection.

The voltage feedback is implemented by means of the transmission of thefeedback signal FB in dependence on the output voltage Vout from theconverter die D2 to the control die D1 and only takes place in onedirection.

Furthermore, the connection between the temperature input and thetemperature output D1_TMP, D2_TMP may also be realized based onbidirectional communication. For this purpose, the connection betweenthe temperature input and the temperature output is likewise produced bymeans of a single-line interface INT3. This interface can be used forreceiving a temperature signal TEMP from the converter die D2, as wellas for transmitting a configuration signal SET from the control die D2to the converter die D2 in another transmitting direction and forswitching the converter die D2 on or off and/or making available a biascurrent at the converter die D2 in dependence on this signal.

The single-line interfaces INT1, INT2 represent a simplified way forcontrolling the DC/DC converters of the converter die D2 in onetransmitting direction and make it possible to receive feedbackinformation such as, for example, the current measured at the converterdie D2 in another transmitting direction. The implementation of theconverter arrangement allows a design with less complexity and a reducedstructural size. The number of required terminals is fewer than insolutions known from the prior art. The influence of thermal factors isreduced because the dissipation of power essentially concerns only oneof the two modules. The implementation is furthermore advantageous for asimpler power supply.

FIG. 2 shows a converter arrangement according to the proposed principlein greater detail. The control die D1 comprises a control logic thatfeatures at least three additional components: a pulse-width modulatorMOD, a return or feedback path and a control path. The input side of thepulse-width modulator MOD is connected to a (not-shown) clock generatorand the output of the second comparator COMP2. A saw-tooth generator GENis also connected to the clock generator. An output of the pulse-widthmodulator MOD is connected to a control side of a first switch SW1, aswell as to a control side of a second switch SW2 via an inverter INV.The first and the second switch SW1, SW2 are connected to one anotherwith their respective load sides by means of a first node N1 and aprecision resistor Rsense. In addition, the first switch SW1 is coupledto a supply terminal VSUP with its other load side. The second switchSW2 is coupled to an additional supply terminal VSS via a second node N2with its other load side.

The control path comprises an operational amplifier OPAMP that isconnected to the first and the second nodes N1, N2 with its input side.The first node N1 is additionally coupled to the control output D1_T1.An output side of the operational amplifier OPAMP is connected to afirst comparator COMP1, as well as to an input of a second comparatorCOMP2 via a summing unit Σ. The first comparator COMP1 is an optionalcomponent that is coupled to the pulse-width modulator MOD with itsoutput side.

The return or feedback path comprises a transconductance amplifier(operational transconductance amplifier) OTA that is connected to thefeedback input D1_F1 with an input side. A reference voltage VREF issupplied to another input side. An output side of the transconductanceamplifier OTA is connected to a grounded parallel circuit that comprisesa first capacitor C1 on one branch and a second capacitor, as well as afirst resistor R1, on another branch. The output side of the operationalamplifier OPAMP is also connected to another input of the secondcomparator COMP2. The saw-tooth generator GEN is ultimately coupled tothe second comparator COMP2 via the summing unit Σ.

The converter die D2 comprises at least one DC/DC converter DCDC1 withat least two interconnected switches SW3, SW4. The switches arerespectively coupled to a converter control logic CCL via a driverstage, wherein the driver stage comprises a p-gate and an n-gate. One ofthe switches SW3 is particularly connected to the converter controllogic CCL with the n-gate and the other switch SW4 is connected to theconverter control logic CCL with the p-gate. The switches SW3, SW4 areconnected in series with their corresponding load sides and with acurrent meter SENSE. In addition, the switches SW3, SW4 are supplied viathe supply terminals VSUP, PVSS.

The interconnected switches are additionally connected to an inductanceterminal LX1. The inductance terminal LX1 may be connected to anexternal coil L1 and grounded by means of a capacitor C. In addition, aconnection node that connects the coil L1 and the capacitor forms afeedback output D2_FB and is connected to the feedback input D1_FB.

The converter die D2 optionally comprises a zero comparator Zcomp thatis connected between one of the switches (in this case SW3) and thecorresponding supply input PVSS.

The embodiment illustrated in FIG. 2 represents a current mode DC/DCconverter (current mode DC/DC converter). The arrangement may beoperated based on the principle of switched DC/DC converters.

Accordingly, the converter utilizes a feedback signal FB that indicatesthe output voltage Vout and is made available by the DC/DC converterDCDC1. The converter utilizes a current signal I_sense that is dependenton the current flowing through the coil D1 via the control path. Thesetwo signals are fed to the second comparator COMP2. In this way, thecontrol signal PWM is generated by means of the pulse-width modulatorMOD in dependence on a comparison signal of the second comparator COMP2.The control signal PWM then serves for controlling the converter die D2,for example, in that it adjusts a duty factor or duty cycle for theDC/DC converter DCDC1. In other words, the control die D1 utilizes afeedback voltage, as well as current information on the coil L1, inorder to generate the control signal PWM.

The mode of operation of the control die D1 is described in greaterdetail below. The proposed mode of operation can be derived from thecurrent mode control principle (current mode control principle). In thiscase, the coil L1 is used as current source in order to reduce dynamicsin the feedback. The control logic sets a current reference due to theutilization of the control signal PWM. The control and the feedbackfollow this reference cycle after cycle.

The control signal PWM, which can be transmitted via the control outputD1_T1, is generated by means of the pulse-width modulator MOD. However,other signal-generating means would also be conceivable. In thisembodiment example, the pulse-width modulator MOD is supplied with aclock signal CLK. In addition, the comparison signal of the secondcomparator COMP2, which can be used for adapting the control signal PWMin dependence on the feedback signal FB and the current signal I_sense,is fed to the pulse-width modulator MOD.

The current signal I_sense is measured in the form of a voltage dropacross the precision resistor sense with the aid of the operationalamplifier OPAMP. The resulting current signal I_sense and the saw-toothsignal SAW are added, wherein the summing unit Σ is used for thispurpose. Subsequently, the current signal is made available at thesecond comparator COMP2. In addition, the current signal I_sense is alsofed to the first comparator COMP1 which, in a manner of speaking,represents a safety component that can indicate a high-current situationat the converter die D2 to the pulse-width modulation. This component isoptional.

The transconductance amplifier OTA compares the feedback signal FB tothe reference Vref. The thusly compared feedback signal FB is fed to theother input of the second comparator COMP2 in the form of an errorsignal. C1, C2 and R1 are used and adjusted in order to compensate theoutput of the transconductance amplifier PTA.

The second comparator COMP2 compares the feedback signal FB and thesummed current signal I_sense in order to respectively generate acorresponding output signal or the comparison signal. In thisembodiment, the comparison signal of the second comparator COMP2particularly is also a pulse-width modulated signal. The pulse-widthmodulator generates the control signal PWM from the comparison signal ofthe second comparator COMP2 and the clock signal CLK. The switches SW1,SW2 open and close in accordance with the modulated control signal PWM.In this way, a duty factor or duty cycle of the converter die D2 isdefined and transmitted to the DC/DC converter DCDC1 via the single-lineinterface INT1.

The mode of operation of the converter die D2 can be further elucidatedwith reference to FIG. 3. FIG. 3 shows an exemplary embodiment of a flowchart of a converter arrangement according to the proposed principle.The drawing shows characteristic signals that are fed to the controloutput D2_T1, to the p-gate and the n-gate, as well as to the inductanceterminal LX1, as a function of the time t.

The control signal PWM is transmitted from the control output. D1_T1 tothe control input D2_T1. At the control input. D2_T1 of the converterdie D2, the control signal PWM is measured by means of the buffer BUFthat in the present embodiment represents a Schmitt trigger. The bufferBUF generates a PGATE signal that is synchronous with the control signalPWM (see signals at the control output D2_T1 and the p-gate in thedrawing) in dependence on the control signal PWM. The PGATE signalcauses the p-gate to open or close the switch SW4. If the switch. SW4 isopened, the current flowing through the coil L1 simultaneouslyincreases, as indicated in the drawing, in the form of a signal rise atthe inductance input LX1 (see signal at LX1 in the drawing).

Due to the feedback and control (see above), the control signal PWM isdynamically adapted. This is indicated in the drawing in the form of asignal rise at the control output D2_T1.

When the PGATE signal is deactivated, the switch SW4 is closed and anNGATE signal is simultaneously activated by means of the convertercontrol logic CCL. The NGATE signal causes the n-gate to open or closethe switch SW3. If the switch SW3 is closed, the current flowing throughthe coil L1 simultaneously decreases, as indicated in the drawing, inthe form of a signal decay at the inductance terminal LX1 (see signal atLX1 in the drawing). If the current flowing through the coil L1 isalmost zero while the NGATE signal is activated, the (optional) zerocomparator Zcomp deactivates the NGATE signal (ideal diode operation)and a new cycle is started.

While the PGATE signal is activated, the coil current is measured andthe current source is used for transmitting a corresponding currentsignal I_sense to the control die D1 by means of the single-lineinterface INT1. This information is used for the control logic, forexample, in order to realize a current mode DC/DC converter.

FIG. 4 shows another embodiment example of a converter arrangementaccording to the proposed principle. The implementation shown is basedon the arrangement described with reference to FIG. 2. However, themeasurement of the current signal I_sense is implemented differently.

In this case, the precision resistor Rsense is coupled between thesecond node N2 and a third node N3 that is connected to the supply inputVSS. The second comparator COMP2 is respectively connected to the secondand the third nodes N3, N2 with its input side. In this way, the currentsignal I_sense is merely measured in the form of a voltage drop acrossthe precision resistor Rsense in contrast to the implementationaccording to FIG. 2, the current signal I_sense is, in a manner of speaking, decoupled, and the transistor SW1 is not involved.

FIG. 5 shows an embodiment example of a multi-phase converter accordingto she proposed principle. This implementation is based on theembodiment example illustrated in FIG. 4. However, the control die andthe converter die D1, D2 comprise additional components in this case.

The control die D1 has a plurality of control logics that are realizedas discussed above and integrated into a common semiconductor body.These components jointly form a multi-phase converter arrangement,wherein each control logic defines a corresponding phase. In thisconcrete embodiment, the control logics respectively share the controland feedback paths. However, it is also possible to provide separatefeedback paths for each of the corresponding control logics or torespectively provide a few control logics with a corresponding feedbackpath, etc.

The converter die D2 essentially corresponds to the converter diediscussed in connection with FIG. 2. However, the converter diecomprises a plurality of converters that are indicated in the form ofboxes in the drawing. These converters may likewise be integrated into acommon semiconductor body or alternatively respective or partiallyseparate semiconductor bodies. As indicated in FIG. 5, they may beconnected via respective feedback outputs D2_FB. In this way, allconverters make available a common output signal Vout. In an alternativeembodiment that is not illustrated in the figures, each converter mayalso make available a different output signal.

The proposed implementation allows flexible adaptation of the converterarrangement for power management purposes. The number of phases canlargely be chosen arbitrarily and adapted to the respective task. Highcurrents can therefore be realized on different power supplies.

FIG. 6 shows an embodiment example of an inverting converter arrangementaccording to the proposed principle. The implementation shown is basedon the concept presented with reference to FIG. 2. In this simplifieddrawing, only a few components of the control die D1 are shown in orderto better highlight the differences.

In this case, the precision resistor Rsense is connected to the firstnode N1 and the first switch SW1 rather than to the second switch SW2.This results in an inverted control signal PWM being fed to the controlinput D1_T1 (see FIG. 7), and therefore represents an alternativeimplementation.

FIG. 7 shows a corresponding example flowchart of a converterarrangement according to FIG. 6.

FIG. 8 shows an embodiment example of another multi-phase converterarrangement according to the proposed principle. In this specialexample, the control die D1 comprises a control logic that is capable ofoperating eight phases, i.e. eight DC/DC converters that form part ofone or more converter dies D2. However, only four DC/DC converters areillustrated in the figure. The control die D1 features a correspondingnumber of control outputs D1_T1, D1_T2 and temperature inputs D1_TMP. Inaddition, a common feedback input D1_FB is provided in this case.Temperature sensors TMP are connected to the temperature outputs D2_TMP,respectively.

Accordingly, the converter die or the plurality of converter dies D2feature/s a corresponding number of control outputs D2_T1, D2_T2 andtemperature outputs D2_TMP. The feedback outputs D2_FB connect theinductance terminals LX1, LX2 and are coupled to the common feedbackinput D1_FB of the control die D1.

The invention claimed is:
 1. A switched DC/DC converter arrangement,comprising: a control die; converter dies; wherein the control diecomprises a control logic for generating a first set of signals andfurther comprises control outputs for controlling the converter dies bymeans of the first set of signals, respectively, wherein each of theconverter dies comprises at least one converter and each of theconverter dies is designed for converting an input signal into an outputsignal in dependence on its respective signal within the first set ofsignals, wherein the first set of signals can be received at a dedicatedcontrol input; and single-line interfaces that each connect the controloutputs to the dedicated control inputs, wherein the control logiccomprises a common feedback input that is connected to feedback outputsof the converter dies in order to receive feedback signals from theconverter dies, wherein the feedback signals are dependent on the outputsignals, wherein the first set of signals are dependent on the feedbacksignal, and wherein the single-line interfaces are designed forbidirectional communication, to exchange between the first set ofsignals and a second set of signals for the controller die and theconverter dies over the single-line interfaces in a bidirectionalmanner, wherein the first set of signals comprises control signals andthe second set of signals comprises current signals.
 2. The switchedDC/DC converter arrangement according to claim 1, wherein thesingle-line interfaces are designed for the bidirectional communicationbetween the control outputs and the control inputs.
 3. The switchedDC/DC converter arrangement according to claim 2, wherein thebidirectional communication is designed for transmitting the first setof signals from the control outputs to the control inputs, and forreceiving the second set of signals from the control inputs at thecontrol outputs, and wherein the second set of signals are dependent onat least one coil current flowing through a coil that can be connectedto at least one of the converter dies.
 4. The switched DC/DC converterarrangement according to claim 3, wherein the control logics of thecontrol dies generate the first set of signals in dependence on thesecond set of signals.
 5. The switched DC/DC converter arrangementaccording to claim 1, wherein the control logic comprises a comparatorthat is coupled to the common feedback input and designed for generatinga comparison signal by comparing the second set of signals and thefeedback signals.
 6. The switched DC/DC converter arrangement accordingto claim 5, wherein the control logic comprises a modulator formodulating the first set of signals by means of pulse-width modulation,wherein the pulse-width modulation is carried out in dependence on thecomparison signal of the comparator, and wherein the modulated first setof signals define a duty factor of the converter dies.
 7. The switchedDC/DC converter arrangement according to claim 1, wherein the converterdies comprise: the at least one converter that comprises switches; aconverter control logic that is connected to the respective controlinput and respectively connected to the switches via driver stages; anda current source that is connected to the respective control input andcoupled to a current meter.
 8. The switched DC/DC converter arrangementaccording to claim 1, wherein the control dies comprise a temperatureinputs, wherein the converter dies comprise temperature outputs, andwherein second single-line interfaces connect the temperature inputs tothe temperature outputs.
 9. The switched DC/DC converter arrangementaccording to claim 8, wherein the second single-line interfaces aredesigned for bidirectional communication between the respectivetemperature inputs and the temperature outputs.
 10. The switched DC/DCconverter arrangement according to claim 8, wherein the converter diescomprise means for generating temperature signals, and wherein thetemperature signals are dependent on the temperature of the respectiveconverter dies and made available at the temperature outputs,respectively.
 11. The switched DC/DC converter arrangement according toclaim 10, wherein the bidirectional communication is designed fortransmitting the temperature signals from the temperature outputs to thetemperature inputs, and for receiving configuration signals from thetemperature outputs at the temperature inputs.
 12. The switched DC/DCconverter arrangement according to claim 11, wherein the control logic,in dependence on the configuration signals, switches the converter dieson or off, and/or makes available a respective bias current at theconverter dies.
 13. The switched DC/DC converter arrangement accordingto claim 1, wherein the control die comprises a plurality of controllogics that respectively comprise a control output, and wherein theconverter die comprises a plurality of converters that respectivelycomprise a control input.
 14. The switched DC/DC converter arrangementaccording to claim 13, wherein the plurality of control logics isintegrated into a common semiconductor chip, and wherein the pluralityof converters is integrated into another common semiconductor chip. 15.The switched DC/DC converter arrangement according to claim 13, whereinthe plurality of control logics comprise the same feedback input, andwherein the feedback input is respectively connected to the feedbackoutputs of the plurality of converters.
 16. A method for operating aswitched DC/DC converter arrangement, comprising the steps of:generating a first set of signals by means of a control logic of acontrol die in order to control converter dies, respectively;transmitting the first set of signals by means of single-line interfacesthat connect a control output of the control die to a control input of arespective one of the converter dies; receiving the first set of signalsat the control input of the respective converter dies; and converting aninput signal into an output signal in dependence on the received firstset of signals by means of at least one converter of the respectiveconverter dies, wherein the single-line interfaces are designed forbidirectional communication, to exchange between the first set ofsignals and a second set of signals for the controller die and theconverter dies over the single-line interfaces in a bidirectionalmanner, and wherein the first set of signals comprises control signalsand the second set of signals comprises current signals.